Changes in proprioceptive systems activity during recovery from post-stroke hemiparesis

Area of Science:

• Neuroscience
• Rehabilitation Medicine
• Medical Imaging

Background:

• Ischaemic stroke, particularly affecting the internal capsule, can impair motor function.
• Understanding the neural mechanisms underlying motor recovery is crucial for effective rehabilitation strategies.

Purpose of the Study:

• To investigate proprioceptive system activity during early motor function recovery after ischaemic stroke.
• To analyze changes in brain activation patterns using functional imaging.

Main Methods:

• A prospective, longitudinal study involving ten patients with unilateral posterior internal capsule infarction.
• Oxygen-15-water positron emission tomography (PET) was used to measure cerebral blood flow during passive index finger extension.
• Brain activation patterns were assessed at two time points: early after stroke and post-rehabilitation.

Main Results:

• Patients demonstrated significant motor function improvement in the paretic limb.
• Passive movement of the non-paretic finger initially activated somatosensory areas (SI and SII) in the non-infarcted hemisphere and ipsilateral SII in the infarcted hemisphere.
• Post-rehabilitation, ipsilateral SII activation in the infarcted hemisphere diminished, restoring a normal pattern. Passive movement of the paretic finger primarily activated SI and SII in the infarcted hemisphere, with additional non-infarcted SII recruitment during rehabilitation.

Conclusions:

• Recovery from internal capsule infarction is associated with notable alterations in proprioceptive system activity for both paretic and non-paretic limbs.
• These neural changes may indicate an inter-hemispheric shift in attention towards proprioceptive stimuli, contributing to motor recovery.